In core-making machines it is indispensable to clean the blowing plates from time to time, for the sand-binder accumulates on such plates and may result in clogging of the sand flow nozzles, which would eventually result in a faulty and defective filling of the core box, to which sand arrives through the blowing plate.
In the type of core-making machines aforesaid, it is consequently necessary to clean the actual blowing plates from time to time, to which end the plates must be extracted from the machines, cleaned and then properly rearranged on said machines.
Now then, these extraction, cleaning and subsequent mounting operations require considerable time periods during which the machine must be stopped, thereby losing on production.
Devices are known to be designed to receive and fix the blowing plates, which may pivot from a horizontal to an upright or near-upright position, to eliminate sand remains, by scraping the plate or otherwise.
Reference could in this sense be made to U.S. Pat. No. 4,572,273 which describes a mechanism provided with a pivoting platform, which pivots due to the assistance of a pair of hydraulic cylinders, which platform and said hydraulic cylinders are associated to a moveable carriage which may travel along vertical guides on a fixed support and with the assistance of another hydraulic cylinder, thereby for the latter cylinder to provide the vertical travel of the platform and consequently of the blowing plate and the core box relative to the top blowing head, whereas the first pair of cylinders allow the platform to pivot for the blowing plate to be cleaned. A fourth hydraulic cylinder, arranged crosswise, allows the blowing plate to be fixed to and released from the pivoting platform.
Although cleaning of the blowing plate is made easier with this solution, the machine still ceases production whilst it is being cleaned. The solution is moreover unduly complex from a structural standpoint.
Another solution may be found in Spanish Patent number 8800929 (U.S. Pat. No. 4,899,802) of the same applicant, which describes a device aimed at making cleaning of the blowing plate easier, which device comprises a frame which may travel vertically along the relevant guides, a tray receiving the blowing plate that is to be removed from the machine to be cleaned being hinged to said frame. A single hydraulic cylinder causes the frame to travel and the tray with the blowing plate fixed thereto to be lowered.
This clearly simple solution does not prevent the machine from remaining inactive either, whilst the blowing plate is being cleaned.